Garage floor over tree root

[malcolm]

I'm planning to build a timber framed double garage. Small enough not to involve planning or building regs. I'm not planning an expensive build - 4*2 probably with feather board cladding sitting on a low brick plinth. The floor can be independent from the wall foundations.

There are currently paving slabs where the garage will go, and they have moved due to a tree root from a mature willow tree. Worried that a concrete floor slab will crack, though it's a mature willow now so maybe the root won't grow much bigger and I can bridge it? What are the options for garage floors over tree roots? It will be a garage more than a workshop but it would be nice to have a base good enough to use a jack.

 

[Barking Mat]

What was @8ob saying recently about round-up and covering it with plastic to prevent animals finding it ?

 

[brightspark]

What was @8ob saying recently about round-up and covering it to prevent animals finding it ?

once roundup hits the soil its inactive after a couple of hours

 

[Kram]

How close is the willow, have a photo?

What was @8ob saying recently about round-up and covering it with plastic to prevent animals finding it ?

For killing a stump. You dont do that to a tree root where the tree is standing near something important...

 

[Agroshield]

What are the options for garage floors over tree roots?

That word 'over' is inadequate for any useful opinion to be expressed.

What is the measurement from the top of the root to the structural slab level of the floor?

 

[8ob]

You can cut back willow roots without killing the tree. You can also dig in a root barrier to stop anything else getting under the slab.

Bob

 

[malcolm]

The edge of the garage would be maybe 6m from the willow so the tree will overhang the garage. I guess the root is pretty big and knowing willows probably not too far under ground level. But I do plan to have the floor level of the garage about 6 inches above current ground level.

I'm keen to work around the tree and don't want to cut the root. Just wondering if there is an obvious solution I have missed. Thinking either a slab with a bit of wiggle room for the root, or maybe just paving.

 

[OJCar]

Suspended timber floor?

 

[cocker]

It's a willow , cut the root .
The tree will be fine and so will your new floor !

 

[AVI_8]

I'm planning to build a timber framed double garage. Small enough not to involve planning or building regs. I'm not planning an expensive build - 4*2 probably with feather board cladding sitting on a low brick plinth. The floor can be independent from the wall foundations.

There are currently paving slabs where the garage will go, and they have moved due to a tree root from a mature willow tree. Worried that a concrete floor slab will crack, though it's a mature willow now so maybe the root won't grow much bigger and I can bridge it? What are the options for garage floors over tree roots? It will be a garage more than a workshop but it would be nice to have a base good enough to use a jack.

I’d say take down the tree, here’s a picture of how down a tree can grow, my son was about 6 at the time, I had to dig down about 5ft to get the whole root out

 

[malcolm]

Might make some sense to chop the root. Doubt it will do the willow much harm and that particular root is also responsible for blocking my drains every now and again. I'll plan for a slab floor.

It's only going to be a timber garage but I want the timber sat off the ground on a little brick plinth and also want the floor level above the ground. Thinking about doing it in 2 stages - a foundation for the plinth maybe 12 inches square set below existing ground level so I can build the brick plinth out of the ground. Then maybe a 4 inch concrete slab for the floor poured on wackered MOT once that is done. Do shout out if any of that sounds daft.

 

[Kram]

Roots need oxygen to breath, the vast majority of a trees root system is within the first foot or two, except for the tap root directly under the tree. They will go deeper if the ground is loose and oxygenated.

If the roots are getting into your drains, that means theres a leak and a way in. They dont just grow through ceramic/brick/concrete/pipes, so at some point may be worth investigation.

 

[brightspark]

Roots need oxygen to breath, the vast majority of a trees root system is within the first foot or two, except for the tap root directly under the tree. They will go deeper if the ground is loose and oxygenated.

If the roots are getting into your drains, that means theres a leak and a way in. They dont just grow through ceramic/brick/concrete/pipes, so at some point may be worth investigation.

but when the roots grow they can press up and bust the ceramic pipes , job i went to tree roots damaged a 150 amp 3 phase armoured cable and had to be renewed at great expense ,took 45 years of growing to damage it

 

[RWD3M]

Might make some sense to chop the root. Doubt it will do the willow much harm and that particular root is also responsible for blocking my drains every now and again. I'll plan for a slab floor.

It's only going to be a timber garage but I want the timber sat off the ground on a little brick plinth and also want the floor level above the ground. Thinking about doing it in 2 stages - a foundation for the plinth maybe 12 inches square set below existing ground level so I can build the brick plinth out of the ground. Then maybe a 4 inch concrete slab for the floor poured on wackered MOT once that is done. Do shout out if any of that sounds daft.

Doesn't sound daft at all, I've done very similar. Don't forget a waterproof membrane under the pour and bring it up the side of the brick/blockwork, adding a DPM on top of the bricks before assembling/building your timber frame. Also, overhang your feather edge at the bottom by an inch or so.

I prefabricated my timber frame from much 4 x 2 and feather edge then just assembled it all in a day (it took 5 of us as it is quite sizeable!), then insulated and lined it over the following weeks/months.

And of course, most importantly, pictures!!!

 

[jo1010]

..... also want the floor level above the ground. ....

Why? For a car garage that's very unusual....You'll need a ramp to get into the garage. If it's more of a shed probably ok.
Normally excavate down for a slab and muck away the spoil.

You'll probably have to trim the root anyway (best solution, and tree will *probably* be ok)..... for your plinth foundations at 12 inches deep. And best to remove the trimmed part of the root completely, else it will rot away and create a void under the floor....

 

[MattF]

Why? For a car garage that's very unusual...

Water doesn't run uphill.

 

[OJCar]

Water doesn't run uphill.

Except when camping in Wales ...

 

[addjunkie]

Why? For a car garage that's very unusual....You'll need a ramp to get into the garage. If it's more of a shed probably ok.
Normally excavate down for a slab and muck away the spoil.

You'll probably have to trim the root anyway (best solution, and tree will *probably* be ok)..... for your plinth foundations at 12 inches deep. And best to remove the trimmed part of the root completely, else it will rot away and create a void under the floor....

Id agree on removing the root. Id not bother digging founds as such for your brick dwarf walls. But excavate, enough to end up with the finished floor about 3 or 4 inches above ground. Whacked hard core base, 6” then a good slab with or with out steel / fibres upto you. Then put an outline of engineering bricks, damp membrane under the slab. Damp course ontop of brick outline. Then build up with timber from there. Mines done in sections, and assembled. Rather than built in situ.
The timber bit needs thought too. Depending if you plan to insulate or not.

You could do a lot worse then copying these

Double Garage from Warwick Buildings

A double garage is made for two cars. Wooden double garages are excellent value and are especially suited for classic cars and motorbikes.

warwickbuildings.co.uk

 

[Argonman]

Here’s my workshop built by me. Lots of trees and tree roots removed before construction. Single garage size, 3x2 frame 4x2 roof members.
4” concrete slab on compacted hardcore with membrane. Timber frame sits on dpm on one layer of engineering bricks. Fully insulated walls and ceiling with 50mm kingspan. Warms up in ten minutes with a fan heater in the coldest parts of winter. Rubber roof covering.

 

[gaz1]

take a look at this as its a slab pour and also a small stem wall pour at the same time and all leveled out for the finish

its a better seal to the garage/shed and its something i like

please note even if the boards was slightly into the concrete slab internally it would give a channel for any water to go elsewhere